Although electrical devices have evolved rapidly over the last few decades, the plants used to generate the electricity that power these devices are still dominated by the use of steam turbines that convert thermal energy, usually from the burning of fossil fuels, into mechanical energy. Even newer solar thermal power plants concentrate the sun’s rays to heat water into high-pressure steam to drive a turbine. But with water not always readily available in locations suited to harnessing solar energy, such as deserts, a new type of solar thermal field, tower and research facility is being built in Australia that requires only air and the sun, making it ideal for parts of the world that receive minimal rainfall.

The technology, developed by Australia’s national science agency theCommonwealth Scientific and Industrial Research Organisation (CSIRO), functions in much the same way as a conventional solar power tower plant. It focuses the sun’s rays with a field of mirrors known as heliostats onto a 30-meter (98 ft) high solar tower. But instead of heating water into steam to power a turbine, the solar Brayton Cycle system uses the concentrated solar energy to heat compressed air, which expands through a 200kW turbine to generate electricity. To overcome sun variability the compressed air can also be heated by natural gas combustion.